Repeating objects along a path
In your scene it looks like the origins of the object might be messed up. When using the Array and Curve Modifier it is important to note that the origin of the curve and the origin of the mesh must be at the same spot. Also the mesh should have it origin at it geometry not somewhere else.

Here is how to fix it:


First let's make sure that your objects are not rotated or scaled by applying the transforms:
Ctrl A -> Rotation &amp; Scale
Select the curve item in object mode
Place the 3d cursor at the curves origin, Shift S -> Cursor to selected
Select the mesh in object mode
Set the origin of the mesh to the geometry, Ctrl Shift Alt C -> Origin to geometry
With the mesh still selected move the mesh to the 3d cursor, Shift S -> Selected to Cursor




blend file